We study the contribution of GNR parameters in effect of SENIRA by molecular overtones. For this we built an analytical model of a confocal ellipsoidal core-shell nanoparticle. In the framework of quasi-static approximation, we express the absorption, scattering, and extinction cross-sections through the particle polarizability [1]}, [2]}:
\(\alpha =\frac{v\left(\varepsilon _{2}-\varepsilon _{m}\right)\left[\varepsilon _{2}+\left(\varepsilon _{1}-\varepsilon _{2}\right)\left(S^{(1)}-f S^{(2)}\right)\right]+f \varepsilon _{2}\left(\varepsilon _{1}-\varepsilon _{2}\right)}{\left(\left[\varepsilon _{2}+\left(\varepsilon _{1}-\varepsilon _{2}\right)\left(S^{(1)}-f S^{(2)}\right)\right]\left[\varepsilon _{m}+\left(\varepsilon _{2}-\varepsilon _{m}\right) S^{(2)}\right]+f S^{(2)} \varepsilon _{2}\left(\varepsilon _{1}-\varepsilon _{2}\right)\right)}\) 
